Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/12—Stretch-spinning methods
  • D01D5/16—Stretch-spinning methods using rollers, or like mechanical devices, e.g. snubbing pins
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
  • D01F6/70—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyurethanes

Definitions

• the present invention relates to a process for the production of a smooth, melt-spun, multifilament elastomer filament a polyurethane and the elastomer filament produced by the process and its use.
• polyimides are incorporated into the polymer chain or added to the polymer melt.
• the continuous filaments produced with the polymer obtained must be wound up at very low speeds and stretched in a second operation, and no information is given about the properties of the filaments obtained.
• DE-A-19 44 507 discloses a multi-stage process which reduces the stickiness of elastomeric polyurethane threads during the spinning process.
• melt extrusion is carried out in a first stage, the thread obtained is solidified by quenching and stretched by at least 30% in a second stage and relaxed by at least 50% in a further stage before winding. From a theoretical point of view, it is stated that in the case of a low relaxation ratio, ie at a faster winding speed, the stickiness of the thread increases.
• the melt-spun thread is stretched and then relaxed again.
• the course of the process indicates that the finished, completely cooled elastomer thread is already present on the take-off godet. This shows the typical properties of a polyurethane elastomer; it can no longer be stretched in the actual sense, but it can be greatly stretched due to its high elasticity
• the stretching process according to DE-A-1944507 remains without a great influence on the thread properties.
• Preferred polyurethanes for producing the elastomer fiber according to the invention are those which are extrudable and which consist of an aromatic diisocyanate, for example 4,4'-diphenylmethane diisocyanate (MDI) and a linear polyether, for example polytetramethylene glycol or an aliphatic polyester for example polybutylene adipate or polycaprolactone diol.
• MDI 4,4'-diphenylmethane diisocyanate
• a linear polyether for example polytetramethylene glycol or an aliphatic polyester for example polybutylene adipate or polycaprolactone diol.
• Block polymers of a cycloaliphatic diisocyanate such as hexahydro-MDI and a linear segmented polyether which are known to be particularly suitable for medical applications, are also suitable.
• the softening point of the suitable polyurethane is between 180 to 230 ° C., the hardness is 80 to 95 ⁇ Shore A and the density is 1.1 to 1.25 g / cm 3. This hardness plays an important role in the tackiness of the polyurethane thread .
• PUR such as the polyether or polyether ester or polyester amine urethanes, provided they have sufficient melt stability, can also be used and melt spun and processed into elastic threads.
• the object of the invention is to produce a high-modulus, high-strength, multifilament elastic thread, the fibrils of which are not glued to one another, by melt spinning.
• the object is achieved according to the invention in that the polyurethane is melt-spun, at the same time irreversibly stretched and wound directly at at least 600 m / min.
• the process according to the invention has surprisingly succeeded in producing multifilament elastomer threads spun from a melt, which can be wound up, with a high initial modulus, the individual fibrils of which are not glued to one another.
• an integrated one-step process ie immediately after spinning the threads, it is wound up with known devices without the need for a further process step, such as relaxing.
• the resulting smooth, elastic thread is suitable for further processing immediately after winding. It has the advantage over the known elastomers that it can be used directly without spinning.
• the process is carried out in such a way that the polyurethane granules are first melted and extruded at 190 to 240 ° C.
• the speed of the winding should be at least 600 m / min, preferably more than 900 m / in, so that a draw ratio of at least 1.5 should be present. Since the drawing and winding take place immediately after the spun thread has been drawn off, the process can practically be referred to as simultaneous, simultaneous or spinning.
• the thread has not yet completely cooled on a first pair of rolls, which still allows an actual stretching in the drawing zone.
• This stretching and thus also greater molecular orientation in the threads is then also manifested by low elongation at break and high cooking shrinkage and in particular a greatly increased modulus.
• the orientation of the molecules in the take-off zone depends on the take-off speed and, due to the strongly temperature-dependent viscosity of the polymers, also to a large extent on the spinning temperature. If the pre-orientation is too low, the module can no longer be increased to the highest values.
• the winding is preferably carried out without voltage.
• This high-modulus, spun-stretched thread can be easily processed into a flat structure. In order to avoid large dimensional losses of the fabric in the equipment, it is advisable to fix it in front of the equipment. The choice of fixing conditions allows the resulting elasticity of the goods to be controlled. Because of the shrinkage present, the thread according to the invention is also particularly suitable for shape fixation.
• the fabric can also in water of at most 130 # C, but advantageously sers at temperatures below the boiling point of the Was ⁇ , for example 94 to 100 C ⁇ are annealed.
• the tempering is preferably carried out using steam, hot water or heated metal surfaces. In order to guarantee sufficient dimensional stability, the tempering should take place at temperatures> 90 * C.
• the elastomer thread Before tempering, the elastomer thread has a modulus of at least 10, preferably> 20, in particular 20 to 40 cN / tex, an elongation at break of 80 to 300%, preferably 90 to 200%, based on the length of the unstretched thread.
• the stretched elastomer thread has a completely reversible elasticity up to the elongation at break.
• the rubber-elastic elastomer thread according to the invention After tempering, the rubber-elastic elastomer thread according to the invention, depending on the type and temperature of the treatment, has an elongation at break of 100 to 800%, in particular 300 to 600%, preferably of about 400%, based on the length of the unstretched thread (see Table 1 and 2).
• the spun-stretched elastomer thread is expediently almost completely reversibly elastic up to the tearing limit.
• Preferred areas of application for the rubber-elastic elastomer thread according to the invention are textile fabrics. It has proven to be advantageous to process the elastomer thread according to the invention together with at least one other non-elastic thread made of synthetic or natural fibers to form an elastic sheet-like structure.
• FIG. 1 shows a schematic flow diagram of the spin-stretching method.
• FIG. 2 force-strain diagrams.
• FIG. 3 hysteresis curves
• a spinning block with spinnerets is shown in FIG.
• a bundle of fibrils 2 is combined into a thread 2 ' on an ensemble pin or a roll 3 and guided over a godet 4 and a separating roll 4', which together form the pair of rolls 4, 4 1 .
• Another pair of rollers 5, 5 ' consists of a godet 5 and a separating roller 5'. 6 with a coil with a drive roller 7 is designated.
• curve 1 shows the cold-spun stretched thread.
• Curves 2 to 4 show the force-elongation of the same thread annealed at different temperatures; Curve 2 at 40 * C, curve 3 at 60 * C and curve 4 at 98 * C in water.
• hysteresis curve 1 of the spun yarn and hysteresis curve 2 of the spun yarn additionally treated at 98 * C in water is shown.
• the elasticity is greater with approximately the same tractive force.
• thermoplastic polyurethane from GOODRICH, Estane 54351 made from an aromatic diisocyanate, a polycaprolactone macrodiol and butanediol with a hardness of 84'Shore A, a softening point of 185 ° C., a density of 1.15 g / cm 3 are the first dried at 6.0 * C for 8h and approx. 50 mbar, then at 90 * C for 24h and under high vacuum to a residual moisture of 0.01%, with an intrinsic viscosity of 1.80, measured in a solvent mixture of 1: 1 phenol / Tetrachloroethane with an Ubbelohde viscometer at 25 * C and concentration of 0.4% results.
• UV absorbers of the Tinuvinvfy type from CIBA GEIGY can be polymerized or powdered onto the granulate. Fillers such as TiO 2 , SiO 2 can be used to improve the elastic properties and the gloss.
• the granulate is melted in the absence of oxygen in an extruder, for example at 210 * C, through a 10 ⁇ m filter sieve and through spinning block 1 with a spinneret with eight holes at a pre-pressure of 60 bar, and in a spin-stretching process to a multifilament dtex 41 f 8 spun.
• the individual filaments 2 are cooled in a blow shaft (not shown) with air of 40 mm water column and brought together and oiled by means of an ensemble pin 3.
• the spinning speed, given by the godet 4, is 600 m / min.
• the thread 2' is guided onto the second pair of rolls 5, 5 'with five loops and cold stretched 2.1 times.
• the cold rollers 4, 5 with a smooth surface are driven with electric motors, not shown, and the counter rollers 4 'and 5 * with air. This keeps the friction resp. the thread tension is so low that the thread 2 'is not distorted.
• the thread 2 ′′ is wound up without tension on a bobbin at a winding speed of 1250 m / min. - 8th -
• the thread is produced by the spin-stretch method.
• thermoplastic polyurethane also based on GOODRICH polyester, Estane 58277, which is suitable for medical applications, with a hardness of 93 "Shore A, a softening point of 185 ° C. and a density of 1.19 g / cm 3 , was spun according to Example 1 and stretched at the same time.
• Tables 1 and 2 summarize the thread properties of Examples 1 and 2.
• ** Module is understood to mean the force at 100% elongation based on the initial titer - 9 -
• the inventive caden 2 '' shows the properties according to the table, 1st column. Its strength is 25 cN / tex, its elongation at break 145% and the boiling shrinkage 61% based on the length of the unstretched thread.
• the thread can also be wound up well. It shows no tendency to stick.
• a microscopic transverse image shows that the individual filaments are well separated from one another and have the desired round cross section.
• this thread shows the properties according to columns 2 to 5 of the table.
• the elongation at break in boiling water (column 5) increases to 490%.
• the elastic properties are comparable to those of the multifilament, commercially available wet-spun polyurethane fibers glued together.
• thermoplastic polyurethane from Example 1 10 kg were spin-stretched using our spin-stretching method with a draw of 600 m or 1600 m / min at various spinning temperatures.
• the spun-stretched original thread can, for example, be knitted together with a polyamide dtex 33 f 10 to form a fabric. After fixing or after a heat treatment, for example dyeing, of this knitted fabric, the product can be processed into a rubber-elastic flat structure in a known manner.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Artificial Filaments (AREA)

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• 1987
  • 1987-12-11 JP JP63500011A patent/JPH0686683B2/ja not_active Expired - Lifetime
  • 1987-12-11 EP EP19870907735 patent/EP0295271B1/de not_active Expired - Lifetime
  • 1987-12-11 WO PCT/CH1987/000169 patent/WO1988004703A1/de active IP Right Grant

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